qualcomm: Add fb notify quirk

This quirk touches the `blank` file of the framebuffer /sys nodes, which
ends up unsuspending things that start suspended until the *right thing*
is happening to not be suspended.

X11, among others, do the right things. It seems other framebuffer
interfaces are not.

This can likely be fixed in other ways, but this is the more
approachable way to me right now.

modules/quirks/qualcomm/default.nix

@@ -2,6 +2,7 @@
   imports = [
     ./framebuffer.nix
     ./msm-dwc3.nix
+    ./msm-fb-notify.nix
     ./wcnss-wlan.nix
   ];
 }

modules/quirks/qualcomm/msm-fb-notify-task.rb

@@ -0,0 +1,10 @@
+class Tasks::MsmFbNotify < SingletonTask
+  def initialize()
+    Targets[:SwitchRoot].add_dependency(:Task, self)
+    add_dependency(:Mount, "/sys")
+  end
+
+  def run()
+    System.write("/sys/class/graphics/fb0/blank", "0")
+  end
+end

modules/quirks/qualcomm/msm-fb-notify.nix

@@ -0,0 +1,24 @@
+{ config, lib, pkgs, ... }:
+
+let
+  cfg = config.mobile.quirks.qualcomm;
+  inherit (lib) mkIf mkOption types;
+in
+{
+  options.mobile = {
+    quirks.qualcomm.fb-notify.enable = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Enable this on a device which requires the framebuffer
+        to be notified for some components to work right.
+
+        The most likely thing this fixes is touch input.
+      '';
+    };
+  };
+
+  config = mkIf (cfg.fb-notify.enable) {
+    mobile.boot.stage-1.tasks = [ ./msm-fb-notify-task.rb ];
+  };
+}